Valve-gear



(No Model.) 2 sheets-sheet 1.

J. B. QUINN.

VALVE GEAR.

Patented Oct. 27, 1885.

" l[Ill y Q INVENTOR:

ATTORNEYS.

(No Model.)

J. B. QUINN. VALVE GEAR.

Patented Oct. 27, 1885.

2 Sheets-Sheet. 2.

WITNESSES graph". whingm. n. c.

ATTORNEYS.

UNITED STATES PATENT OEETCE,

JAMES BAIRD QUINN, OF ST. PAUL, MINNESOTA.

VALVE-GEAR.

SPECIFICATION forming part of Letters Patent NO. 329,338, dated October 27, 1885.

Application filed August 7, 1885. Serial No. 173,830. (No model.)

T0 all whom it may concern:

Be it known that l, JAMEs BAIED QUINN, of St. Paul, in the county of Ramsey and State of Minnesota, have invented a new and ImprovedValve-Gear for Steam -Engines, of which the following is a full, clear, and exact description.

The object of my invention is to provide a new and improved steam-engine, which is especially adapted for river-steamers propelled by a stern wheel turned by a high-pressure engine upon one side and low-pressure engine on the other.

The invention consists of two swinging arms deriving their motion from the wheel-shaft by suitable connections,of two arms which impart motion to the slide-valve and automatically cut off the steam by adjustable dogs placed on segments, and of a device for regulating the position ot' the dogs on the segments.

The invention consists of various parts and details,hereinafter more fully set forth and described.

Reference is to be had to the accompanying drawings, forming part of this speciiication, in which similar letters of reference indicate corresponding parts in all the iigures.

Figure lis a vertical side elevation,partly in section, of my improvement. Fig. 2 is a plan view of the same, partly in section. Fig. 3 is a vertical cross-section on the lines x x of Fig. l. Fig.4 is a vertical cross-section on the lineg/y of Fig. 5. Fig. 5 is a bottom view of the cut-off mechanism.

The steam-cylinder A is provided on each end with the ports ce and the steam-chests B B, in eachof whichis placed a sliding valve,C, actuated by means of the valve-rod D, from the valve-gear E, placed between the steam-chests B B, and supported above the center ofthe cylinder A. The balance-valve C is provided with a packing-ring, C', resting in a groove, C2, formed on the top ofthe valve and backed by a suitable elastic packing,03,which is pressed against the ring C by a follower, 0*, with a ^shaped upper surface and supported by springs, and the steam which enters the groove C', by suitable apertures in the bottom of the groove C. The valve Gis also provided with the exhaust-cavity C5, which connects with the exhaust-chamber b by means of the exhaust-port b.

Centrally between the steam-chests B B is mounted on suitable bearings the shaft F, which receives a rocking motion from the eccentrics on the wheel-shaft by means of suitably-jointed rods attached to the crank F, keyed on the shaft F. On the shaft F are keyed the arms G, extending downward and in line with the crank F', and swinging loosely on the shaft F are the two link-arms H H, which are each connected to their respective valve-rods D by the links H and the lugs H2. Each lng H2 is tapped and screws on the valve-rod D, and is secured on the same in any desired position by jam-nuts. Theinner ends ofthe valve-rods D are supported in suitable keepers, D', bolted to the plate B, fastened to the steam chests B B. Eachdriving-arm G is provided on its lower end with a notched piece, G, and each link-arm H is provided with a rod, I, placed in lugs cast on the outside of the arm H, and having a spring, I, which keeps the rod I in proper position, and allowing an upward motion of the rod I when disengaging the arm G. The lower end of the rod I forms into the right-angle arm IL turned inward, which is engaged by the notched piece G on the arm G, when the latter is in a vertical position and passing the center. To each side of the plate B is attached a segmental arm, J, on which is placed, and adjustable thereon, the trippingdog K. The under side of the cross-plate B is provided with grooves B2, in which slide the two racks L, held on the plate B by suitable keepers, L. Each rack is provided with a slotted arm, L2, in which extends a stud, K, secured to the lower end of the tripping-dog K. The racks L are moved in opposite directions at the same time by the pinion M, placed between the racks L on the plate B', and provided with a hand-wheel, M. The pinion is locked in any position by the spring-latch M2. The valve-rod D projects beyond the outer end of the steam-chest B, and is provided on its extreme end with the enlargement D2, which has a bearing on the keeper N, `held in place by the rods N, secured to steam chests B. Keeper N is provided with the dash-pot O, of usual construction, vented and regulated by IOO stop-cocks in the ordinary way, and having rod D is returning, the dash-pot O, under theV pressure of the spring N2, moves with the piston-rod until seated in the keeper N, after which the valve-rod may move freely without any connection with the dash-pot O. The enlarged part D2 of the valve-rod D is provided with a square projection, D3, by which the valve-'rod D may be turned and the slide valve C adjusted without removing the cover of' the steam-chest B. The dash-pot is-shown as placed entirely outside of the steam-chest B5but it can be attached directly to the steamchest B, and the rods and spring placed'inside.

" The operation is as follows: The rocking.

shaft F imparts a swinging motion to the arms G. The movement of both being alike, it is `only necessary to describe the operation of one arm. The arm G on passing the center in the direction of the arrow a' engages with its notched piece G the angular arm I2 of the bolt I, placed on the arm H, and carries the latter with it until the angular arm I2 is released by striking the tripping-dog K, and returns ,to its former position by the pressure of the spring N2 on the rods N'. This movement of the arm H causes the valve C to open the port a and admit steam to the one end of the cylinder A, and cut oft" the steam according to the position of the dog K on the segment J. It will be seen that the dogs K are adjusted on the segment J by turning the hand-wheel M', which causes a movement of the racks L in an opposite direction from each other, whereby the dogs K approach or recede from the ends of their segments. The dogs K are thus adjusted simultaneously for any desired points 'ofcut-off; o'r they may be run out to the ex tremities of the segments J and completely out of reach of the bolt I, in which case the steam would follow the piston through its full stroke, thereby acting as a simple slide-valve engine. rIhe position of the dogs K on the segments J permits a very nice adjustment of the point of cut-off without requiring an extraordinary degree of excellence in the construction of the several parts, which are simple and easy to construct, and can be readily repaired in case of necessity with such skill and appliances as are ordinarily to be found in any steamboat. On the return motion of the arm G in the inverse direction of the arrow a', the arm H is again engaged by the swinging arm G and carried with the same its entire stroke, whereby the valve C moves in the direction of the arrow d' and connects the ports a and b', and thereby exhausts the steam. It will be seen that when the valve C travels in the direction of the arrow a' the valve-rod carries the dash- Having thus described my invention, whatv I claim as new, and desire to secure by Letters Patent, is-

' l. In a steam-engine, the swinging arms G, deriving their motionrby suitable connections from the wheel-shaft, in combination with the arms H, the segment J, the dogs K, the links H', the lugs H2, the valve-rodA D, the balanced slide-valve C, and the cylinder A, substantially as shown and described. y

2. In a steam-engine, the swinging arm G, provided with the notched piece G', in combination with the arm H, the rod I, the link H', the lug H2, the valverod D, and the balanced slide-valve C, substantiallyas shown and described.

3. In a steam-engine, the swinging arm G, provided with the notched piece G', in combination with the arm H, the rod I, the an gular arm I2, the spring I', the segment J, and the dog K, substantially as shown and described.

4. In a steam-engine, the swinging arm G, provided with the notched arm G', the arm H, the rod I, the angular arm I2, the spring I', the segment J, and the dog K, in combination with the link H', the adjustable lug H2, the valve-rod D, the slide-valve C, the keeper N, the springs N2, the dash-pot O, and the yoke O',substantiallyias shown and described.

5. In a steam-engine, the arm G, the arm H, the segment J, the dog K, the valve-rod IOO D, the slide-valve C, the keeper N, the rodsy N', the spring N2, the dash-pot O, and the yoke O', in combination with the cylinder A, the inlet-port a, and the exhaust-port b', substantially as shown and described.

6. YIn a steam-engine, the segments J, the

dogs K, and tliestuds K', in combination with the slotted keepers L2, the racks L, and

the pinion M, substantially as shown and described.

7. In a steam-engine, the arms G and H,

lthe rod I, the angular arm I2, and the spring I', in combination with the segments J, the dog K, ,the studs K', the keepers L2, the racks L, the pinion M, and the hand-wheel M', substantially as shown and described.

8. In a steam-engine, the segments J, the dogs K, andl the studs K', in combination with the slotted keepers L2, the racks L, the keepers L', the pinion M, the hand-wheel M',

and the spring-latch M2, substantially as shown f and described.

J AMES BAIRD QUINN.

Witnesses:

A. B. ROBERT, M. A. LE BLANC. 

